Technical Abstract:
Southern highbush blueberries (SHB) (Vaccinium corymbosum L.) are mostly hand harvested for the fresh market. Hand harvesting of blueberry is labor intensive and costly. Efforts are under way to develop blueberry genotypes that will develop less bruising after impact with hard surfaces on the harvesters. In this study, the fruit of ‘Farthing’, ‘Scintilla’, ‘Sweetcrisp’, and new SHB selections were either hand-harvested or machine-harvested and assessed during postharvest storage for bruise damage, disease incidence and softening. Studies showed that ground-loss that occurred during machine harvesting can be reduced by modifying the blueberry plant architecture. Fruit drop tests from a height of 40 inches on plastic surface showed that a soft-textured, conventional-flesh genotype (‘Scintilla’) was more susceptible to bruising than the crispy-flesh genotypes (‘Farthing’, ‘Sweetcrisp’, and FL 05-528). When the contact surface was cushioned with ‘Poron’ foam sheet, bruise incidence was significantly reduced in all genotypes. Also, the fruit dropped 40 inches developed more bruise damage than those dropped 20 inches. Machine harvesting contributed to bruise damage in the fruit and softening in storage. Fruit firmness in crispy-type SHB was higher than in soft-textured SHB. Further modifications to mechanical harvesters and blueberry plant architecture are necessary to improve the quality of machine-harvested blueberries and the over harvest efficiency.